With the continuous development of communication technology and electronic information technology, positioning technology has been paid more and more attention. high-accuracy positioning need is also more and more obvious, especially high-accuracy positioning and indoor positioning needs.
With regard to Global Positioning System (GPS) positioning technology, due to signal loss and other reasons, a signal becomes weak indoors, making a positioning terminal unable to find enough satellites; a cellular network system cannot achieve sufficient accuracy outdoors or indoors because of the large positioning error, and so it cannot meet a wireless positioning requirement.
Improving wireless positioning accuracy depends mainly on two factors: the synchronization precision of each node that transmits a positioning signal, and the ranging accuracy. The synchronization of a navigation satellite is accomplished by setting up a control station with good space conditions on the ground, the control station and the satellite have a good visual condition therebetween.
In order to solve the indoor high-accuracy positioning problem, we need to establish a wireless positioning system on the ground. Each signal-positioning station of a ground wireless positioning system is located close to the ground, this is susceptible to the sheltering and reflection by a variety of buildings on the ground. Therefore, if an unified control station is used to complete the synchronization between the signal-positioning stations, complex conditions of the ground will lead to poor synchronization accuracy, and ultimately affect the positioning accuracy.
In the prior art, the accuracy of the synchronization between nodes often cannot meet expectations due to the problems of reflection processing and multipath. Therefore, if an improvement to the positioning accuracy is required, it is necessary to solve the problem of improving the accuracy of the synchronization between the nodes that perform positioning processing.